package playletchaptermod

import (
	"context"
	"fmt"
	"strings"
	"time"
	"videoweb/pub/common/log"
	"videoweb/pub/common/srvdef"
	"videoweb/pub/mongos"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

var coll *mongos.Collection

const duplicatePlayletChapterMsg = "短剧剧集已存在"

// Init 初始化 playlet_chapter 集合和常用查询索引
func Init(ctx context.Context) {
	coll = mongos.Shop.Coll(TN.PlayletChapter)
	initIndex(ctx)
}

func initIndex(ctx context.Context) {
	commonIndexes := []mongo.IndexModel{
		{
			Keys: bson.D{
				{Key: FN.PlayletChapter.PlayletId, Value: 1},
				{Key: FN.PlayletChapter.CurrentEpisode, Value: 1},
			},
		},
		{
			Keys: bson.D{
				{Key: FN.PlayletChapter.PlayletId, Value: 1},
				{Key: FN.PlayletChapter.CreatedAt, Value: -1},
			},
		},
		{
			Keys: bson.D{
				{Key: FN.PlayletChapter.CreatedAt, Value: -1},
				{Key: FN.PlayletChapter.Id, Value: -1},
			},
		},
		{
			Keys: bson.D{
				{Key: FN.PlayletChapter.WatermarkStatus, Value: 1},
				{Key: FN.PlayletChapter.CreatedAt, Value: -1},
			},
		},
		{
			Keys: bson.D{
				{Key: FN.PlayletChapter.MediaSourceId, Value: 1},
			},
			Options: options.Index().
				SetPartialFilterExpression(bson.M{
					FN.PlayletChapter.MediaSourceId: bson.M{"$gt": ""},
				}),
		},
	}
	if _, err := coll.CreateIndex(ctx, commonIndexes); err != nil {
		panic(fmt.Sprintf("(playletchaptermod:initIndex) Create Index failed! err:%+v:", err))
	}

	uniqueIndexes := []mongo.IndexModel{
		{
			// 反向键序避免和线上已有 playletId_1_currentEpisode_1 普通索引冲突，同时兜住同一短剧同一集数的并发重复写入。
			Keys: bson.D{
				{Key: FN.PlayletChapter.CurrentEpisode, Value: 1},
				{Key: FN.PlayletChapter.PlayletId, Value: 1},
			},
			Options: options.Index().
				SetName("uniq_playlet_chapter_episode").
				SetUnique(true),
		},
		{
			Keys: bson.D{
				{Key: FN.PlayletChapter.PlayletId, Value: 1},
				{Key: FN.PlayletChapter.MediaContentId, Value: 1},
			},
			Options: options.Index().
				SetUnique(true).
				SetPartialFilterExpression(bson.M{
					FN.PlayletChapter.MediaContentId: bson.M{"$gt": 0},
				}),
		},
	}
	for _, index := range uniqueIndexes {
		if _, err := coll.CreateIndex(ctx, []mongo.IndexModel{index}); err != nil {
			if isPlayletChapterDuplicateIndexErr(err) {
				log.Warn("短剧章节唯一索引创建失败，请先清理历史重复章节数据", log.E(err), log.Any("index", index.Keys))
				continue
			}
			panic(fmt.Sprintf("(playletchaptermod:initIndex) Create Unique Index failed! err:%+v:", err))
		}
	}
}

// isPlayletChapterDuplicateIndexErr 判断唯一索引创建时是否命中历史重复数据。
func isPlayletChapterDuplicateIndexErr(err error) bool {
	if err == nil {
		return false
	}
	return mongo.IsDuplicateKeyError(err) || strings.Contains(err.Error(), "E11000 duplicate key error")
}

// InsertOnePlayletChapter 插入一条章节数据
func InsertOnePlayletChapter(ctx context.Context, doc *PlayletChapter) *srvdef.SrvErr {
	if doc.Id == 0 {
		doc.Id = mongos.Lid.PlayletChapter.Get()
	}
	now := time.Now()
	if doc.CreatedAt.IsZero() {
		doc.CreatedAt = now
	}
	doc.UpdatedAt = now
	if _, err := coll.InsertOne(ctx, doc); err != nil {
		if mongo.IsDuplicateKeyError(err) {
			return duplicatePlayletChapterErr()
		}
		log.Warn("playletchaptermod:InsertOnePlayletChapter failed", log.Any("doc", doc), log.E(err))
		return srvdef.New(srvdef.ErrDbInsertError, "", "")
	}
	return nil
}

// InsertManyPlayletChapter 批量插入章节数据
func InsertManyPlayletChapter(ctx context.Context, docs PlayletChapterList) *srvdef.SrvErr {
	data := make(PlayletChapterList, 0, len(docs))
	now := time.Now()
	for _, doc := range docs {
		if doc == nil {
			continue
		}
		if doc.Id == 0 {
			doc.Id = mongos.Lid.PlayletChapter.Get()
		}
		if doc.CreatedAt.IsZero() {
			doc.CreatedAt = now
		}
		doc.UpdatedAt = now
		data = append(data, doc)
	}
	if len(data) == 0 {
		return nil
	}
	if _, err := coll.InsertMany(ctx, &data); err != nil {
		if mongo.IsDuplicateKeyError(err) {
			return duplicatePlayletChapterErr()
		}
		log.Warn("playletchaptermod:InsertManyPlayletChapter failed", log.Any("count", len(data)), log.E(err))
		return srvdef.New(srvdef.ErrDbInsertError, "", "")
	}
	return nil
}

// duplicatePlayletChapterErr 返回章节唯一约束冲突的统一业务错误。
func duplicatePlayletChapterErr() *srvdef.SrvErr {
	return srvdef.New(srvdef.ErrDbInputExist, duplicatePlayletChapterMsg, duplicatePlayletChapterMsg)
}

// DelOnePlayletChapter 删除一条章节数据
func DelOnePlayletChapter(ctx context.Context, filter bson.M) (int64, *srvdef.SrvErr) {
	count, err := coll.DeleteOne(ctx, filter)
	if err != nil {
		log.Warn("playletchaptermod:DelOnePlayletChapter failed", log.E(err), log.Any("filter", filter))
		return 0, srvdef.New(srvdef.ErrDbDeleteError, "", "")
	}
	return count, nil
}

// DelManyPlayletChapter 按条件批量删除章节数据
func DelManyPlayletChapter(ctx context.Context, filter bson.M) (int64, *srvdef.SrvErr) {
	count, err := coll.DeleteMany(ctx, filter)
	if err != nil {
		log.Warn("playletchaptermod:DelManyPlayletChapter failed", log.E(err), log.Any("filter", filter))
		return 0, srvdef.New(srvdef.ErrDbDeleteError, "", "")
	}
	return count, nil
}

// FindOnePlayletChapter 查询一条章节数据
func FindOnePlayletChapter(ctx context.Context, filter bson.M, opts ...*options.FindOneOptions) (*PlayletChapter, *srvdef.SrvErr) {
	var doc PlayletChapter
	if err := coll.FindOneEx(ctx, &doc, filter, opts...); err != nil {
		if err != mongo.ErrNoDocuments {
			log.Warn("playletchaptermod:FindOnePlayletChapter failed", log.E(err), log.Any("filter", filter))
			return nil, srvdef.New(srvdef.ErrDbQueryError, "", "")
		}
		return nil, srvdef.New(srvdef.ErrNoData, "", "")
	}
	return &doc, nil
}

type firstChapterRow struct {
	PlayletId int64 `bson:"_id"`
	ChapterId int64 `bson:"chapterId"`
}

// FirstChapterIDs 按集数取每部短剧第一集的章节 ID，排序与详情页选集列表一致。
func FirstChapterIDs(ctx context.Context, playletIDs []int64) (map[int64]int64, *srvdef.SrvErr) {
	out := make(map[int64]int64, len(playletIDs))
	if len(playletIDs) == 0 {
		return out, nil
	}
	const batchSize = 500
	for start := 0; start < len(playletIDs); start += batchSize {
		end := start + batchSize
		if end > len(playletIDs) {
			end = len(playletIDs)
		}
		pipeline := []bson.M{
			{"$match": bson.M{
				FN.PlayletChapter.PlayletId: bson.M{"$in": playletIDs[start:end]},
				FN.PlayletChapter.Status:    StatusUp,
			}},
			{"$sort": bson.D{
				{Key: FN.PlayletChapter.CurrentEpisode, Value: 1},
				{Key: FN.PlayletChapter.Id, Value: 1},
			}},
			{"$group": bson.M{
				"_id":       "$" + FN.PlayletChapter.PlayletId,
				"chapterId": bson.M{"$first": "$_id"},
			}},
		}
		rows := make([]firstChapterRow, 0)
		if err := coll.Aggregate(ctx, &rows, pipeline); err != nil {
			log.Warn("playletchaptermod:FirstChapterIDs failed", log.E(err), log.Any("count", end-start))
			return nil, srvdef.New(srvdef.ErrDbQueryError, "", "")
		}
		for _, row := range rows {
			if row.PlayletId > 0 && row.ChapterId > 0 {
				out[row.PlayletId] = row.ChapterId
			}
		}
	}
	return out, nil
}

// FindManyPlayletChapter 按条件查询多条章节数据
func FindManyPlayletChapter(ctx context.Context, filter bson.M, opts ...*options.FindOptions) (PlayletChapterList, *srvdef.SrvErr) {
	data := make(PlayletChapterList, 0)
	if err := coll.Find(ctx, &data, filter, opts...); err != nil {
		log.Warn("playletchaptermod:FindManyPlayletChapter failed", log.E(err), log.Any("filter", filter))
		return nil, srvdef.New(srvdef.ErrDbQueryError, "", "")
	}
	return data, nil
}

// CountPlayletChapter 统计满足条件的章节数量
func CountPlayletChapter(ctx context.Context, filter bson.M, opts ...*options.CountOptions) (int64, *srvdef.SrvErr) {
	count, err := coll.Count(ctx, filter, opts...)
	if err != nil {
		log.Warn("playletchaptermod:CountPlayletChapter failed", log.E(err), log.Any("filter", filter))
		return 0, srvdef.New(srvdef.ErrDbQueryError, "", "")
	}
	return count, nil
}

// UpdateOnePlayletChapter 更新一条章节数据
func UpdateOnePlayletChapter(ctx context.Context, filter bson.M, update bson.M) *srvdef.SrvErr {
	result, err := coll.UpdateOne(ctx, filter, update)
	if err != nil {
		if mongo.IsDuplicateKeyError(err) {
			return duplicatePlayletChapterErr()
		}
		log.Warn("playletchaptermod:UpdateOnePlayletChapter failed", log.E(err), log.Any("filter", filter))
		return srvdef.New(srvdef.ErrDbUpdateError, "", "")
	}
	if result.MatchedCount != 1 {
		return srvdef.New(srvdef.ErrNoData, "", "")
	}
	return nil
}

// IsLinkedMedia 是否短剧媒资：显式标记或已挂到剧集
func IsLinkedMedia(ctx context.Context, isPlaylet bool, ids ...string) bool {
	if isPlaylet {
		return true
	}
	return ExistsByMediaIDs(ctx, ids...)
}

// ExistsByMediaIDs 判断媒资 ID 是否属于短剧剧集（mediaSourceId / mediaTaskId）
func ExistsByMediaIDs(ctx context.Context, ids ...string) bool {
	clean := uniqueNonEmptyStrings(ids)
	if len(clean) == 0 {
		return false
	}
	item, _ := FindOnePlayletChapter(ctx, bson.M{
		"$or": []bson.M{
			{FN.PlayletChapter.MediaSourceId: bson.M{"$in": clean}},
			{FN.PlayletChapter.MediaTaskId: bson.M{"$in": clean}},
		},
	}, options.FindOne().SetProjection(bson.M{FN.PlayletChapter.Id: 1}))
	return item != nil
}

func uniqueNonEmptyStrings(ids []string) []string {
	if len(ids) == 0 {
		return nil
	}
	seen := make(map[string]struct{}, len(ids))
	out := make([]string, 0, len(ids))
	for _, id := range ids {
		id = strings.TrimSpace(id)
		if id == "" {
			continue
		}
		if _, ok := seen[id]; ok {
			continue
		}
		seen[id] = struct{}{}
		out = append(out, id)
	}
	return out
}

// UpdateManyPlayletChapter 批量更新章节数据
func UpdateManyPlayletChapter(ctx context.Context, filter bson.M, update bson.M) *srvdef.SrvErr {
	result, err := coll.UpdateMany(ctx, filter, update)
	if err != nil {
		if mongo.IsDuplicateKeyError(err) {
			return duplicatePlayletChapterErr()
		}
		log.Warn("批量更新短剧章节数据失败", log.E(err), log.Any("filter", filter))
		return srvdef.New(srvdef.ErrDbUpdateError, "", "")
	}
	if result.MatchedCount == 0 {
		return srvdef.New(srvdef.ErrNoData, "", "")
	}
	return nil
}